RFC 2822 Internet Message Format 3 years ago.
Although, I thought to test the email server.
Used a Free Online Email Server Test. (There is no specific reason for choosing this tool - Google has provided it)
Entered the email address and Sent for Checking.
And Tried another Valid Email Address and It looks like this.
Note: If some one provides the SMTP Email Address. Make sure you test it without sending an email.